Research conducted the last 2.5 years on this project with institutionalized mentally retarded populations has shown significant increases in abnormal movement as rated by nurses in a group of residents being withdrawn from psychotropic medication in comparison with a group of residents remaining on medication. The tardive dyskinesia rating scale developed in this project, DIS-CO (Dyskinesia Identification System - Coldwater), has shown satisfactory interjudge reliability, but it is planned to revise it and shorten it to save rater time and make it more practical. An attempt to standardize the revised scale will be made using a panel of tardive dyskinesia experts to judge the quality and severity of specific movements as a standard for training subsequent raters. Standard workshop training and self instructional techniques will be examined to ascertain the most practical and efficient method of training new raters for widespread use of the DIS-CO scale. At the University of Pittsburgh, the study of naturally occurring medication and dosage changes on target behavior, rating of abnormal movement, and 1 arning performance will continue. Because differential diagnosis of stereotypic and dyskinetic movements is a problem, an attempt will be made to develop a stereotypy rating scale to distinguish these movements from those tardive dyskinetic movements identified by DIS-CO. After the stereotypy ratang scale is developed, settings will be selected which should show differential increase or decrease in both kinds of movements to aid in validating the scales and diagnosing the two conditions. In the state-operated facilities in Minnesota where the project has been conducted, research will begin on developing a tardive dyskinesia monitoring system. Since psychotropic drug usage in community group home seems to be higher than in institutions, a project on developing a tardive dyskinesia monitoring system for community facilities will begin.